Vista - <serviceSecurityAudit> logs success but not failure

I have the following element setup in my web config file:

<serviceSecurityAudit suppressAuditFailure="false"
auditLogLocation="Default"
messageAuthenticationAuditLevel="SuccessOrFailure"
serviceAuthorizationAuditLevel="SuccessOrFailure" />

and I get log entries for successful authorizations in the application
event log, but nothing for failed attempts. Additionally, I do not
get any entries for the authentication process. Has anyone else had
problems with this? Is there something that needs to be done to
enable success logging and authentication logging specifically? Do I
need to handle failed attempts in a specific way (i.e. throw specific
exception)?

Here is the rest of my configuration for authentication and
authorization:

<services>
<service name="WCFTestService.service1"
behaviorConfiguration="service1Behavior">
<endpoint contract="WCFTestService.Iservice1"
binding="wsHttpBinding"/>
<endpoint contract="IMetadataExchange"
binding="mexHttpBinding" address="mex" />
</service>
</services>

<behaviors>
<serviceBehaviors>
<behavior name="service1Behavior" >
<serviceDebug includeExceptionDetailInFaults="true" />
<serviceMetadata httpGetEnabled="true" />
<serviceCredentials>
<userNameAuthentication
userNamePasswordValidationMode="Custom"
customUserNamePasswordValidatorType="IHS.Core.Security.WCF.CoreUserNamePasswordValidator,
IHS.Core.Security.WCF"/>
<serviceCertificate findValue="localhost"
storeLocation="LocalMachine" storeName="My"
x509FindType="FindBySubjectName"/>
</serviceCredentials>
<serviceSecurityAudit suppressAuditFailure="false"
auditLogLocation="Default"
messageAuthenticationAuditLevel="SuccessOrFailure"
serviceAuthorizationAuditLevel="SuccessOrFailure" />
<serviceAuthorization
impersonateCallerForAllOperations="false"
principalPermissionMode="Custom" roleProviderName=""
serviceAuthorizationManagerType="">
<authorizationPolicies>
<add
policyType="IHS.Core.Security.WCF.AccessControlAuthorizationPolicy,
IHS.Core.Security.WCF"/>
</authorizationPolicies>
</serviceAuthorization>
</behavior>
</serviceBehaviors>
</behaviors>